title: Anterior pituitary progenitor cells express costimulatory molecule 4Ig-B7-H3.
abstract: Stem/Progenitor cells in the postnatal pituitary gland are embedded in a marginal cell layer around Rathke's pouch. However, the nature and behavior of anterior pituitary progenitor cells remain unclear. We established bovine anterior pituitary progenitor cell line (BAPC)-1 from the anterior pituitary gland, which expressed stem/progenitor cell-related genes and several inflammatory cytokines. To characterize and localize these pituitary progenitor cells, we produced a mAb (12B mAb) against BAPC-1. The 12B mAb recognized the 4Ig-B7-H3 molecule, which is a costimulatory molecule and negative regulator in T cell activation. WC1(+) gammadelta T cells in young bovine PBMC express the 4Ig-B7-H3 molecule, but few or no 4Ig-B7-H3-immunoreactive cells are expressed in PBMC in adult cattle. The 12B-immunoreactive cells in the bovine anterior pituitary gland were localized around Rathke's pouch and expressed IL-18 and MHC class II. However, the number of 12B-immunoreactive cells was lower in adult than in young cattle. BAPC-1 expressed IL-18 and MHC class II, and demonstrated phagocytotic activity. BAPC-1 also had the ability to promote CD25 expression in PBMC after 5 days of coculture, and blocking 4Ig-B7-H3 x 12B mAb enhanced their expression of CD25. In addition, the 12B-immunoreactive cells were observed around the pars tuberalis closely bordering the median eminence and in the blood vessels of the primary portal plexus in the anterior pituitary gland. These results suggest that an established BAPC-1 may originate from these progenitor cells, and that the progenitor cells with 4Ig-B7-H3 may play a critical role in the immunoendocrine network.
authors.affiliation: Laboratory of Functional Morphology, Tohoku University, Sendai, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Nagai
authors.forename: Hisashi
authors.initials: H
authors.lastname: Aso
authors.forename: Hideki
authors.initials: H
authors.lastname: Ogasawara
authors.forename: Sachi
authors.initials: S
authors.lastname: Tanaka
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Taketa
authors.forename: Kouichi
authors.initials: K
authors.lastname: Watanabe
authors.forename: Shyuichi
authors.initials: S
authors.lastname: Ohwada
authors.forename: Michael T
authors.initials: MT
authors.lastname: Rose
authors.forename: Haruki
authors.initials: H
authors.lastname: Kitazawa
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamaguchi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D060887:B7 Antigens; D002417:Cattle; D005260:Female; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D055099:Neuroendocrine Cells / Q000276:immunology / Q000378:metabolism; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D011971:Receptors, Immunologic / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D013234:Stem Cells / Q000276:immunology* / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; D060887:B7 Antigens; C423237:CD276 protein, human; D012333:RNA, Messenger; D011971:Receptors, Immunologic